Leg fat mass as measured by dual X-ray absorptiometry (DXA) impacts insulin resistance differently in obese women versus men.
OBJECTIVE
To investigate the association between regional fat mass (FM) and insulin resistance and dyslipidaemia in obese women and men.


METHODS
Body composition was measured by dual-energy X-ray absorptiometry (DXA) in 109 obese women and 113 obese men. Insulin resistance was measured by (HOMA-IR); insulin sensitivity was estimated by metabolic clearance rate (MCRestOGTT) and insulin secretion by HOMAsecr. Serum lipids were assessed.


RESULTS
In women, leg FM was negatively (favourably) associated with HOMA-IR and cholesterol/HDL-cholesterol ratio (p<0.05). Trunk FM was positively (unfavourably) associated with HOMA-IR. Leg/trunk FM ratio was negatively associated with HOMA-IR (p<0.001), cholesterol/HDL-cholesterol ratio (p<0.001) and triglycerides (p<0.01); positively (favourably) with MCRestOGTT (p<0.01) and HDL-cholesterol (p<0.05). No associations were found in men. In women, multiple regression analysis demonstrated that leg/trunk FM ratio was the only explanatory FM for HOMA-IR and MCRestOGTT (R(2) = 0.23 and R(2) = 0.13, respectively; p<0.001), but postmenopausal status was also of importance (R(2) = 0.23, p = 0.019 and R(2) = 0.29, p = 0.015, respectively).


CONCLUSIONS
Leg FM has a favourable influence on insulin resistance and dyslipidaemia in obese women, but not demonstrated in this cohort of obese men.
Aasen
Gunnar
G
Spesialistsenteret Pilestredet Park, Pilestredet Park, Oslo, Norway. g.aasen@usa.net
Fagertun
Hans
H
Tonstad
Serena
S
Halse
Johan
J
D015502:Absorptiometry, Photon / Q000379:methods*; D000273:Adipose Tissue / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance; D007866:Leg; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000000981:diagnostic imaging* / Q000503:physiopathology; D017698:Postmenopause; D017697:Premenopause; D012044:Regression Analysis